double non-return valve

例句：

1. 1.The double non-return valve is crucial for maintaining the integrity of the pipeline system.
   双回压阀对于保持管道系统完整性至关重要。
2. 2. During the installation process, it is important to ensure that the double non-return valve is properly installed and functioning correctly.
   在安装过程中，确保双回压阀正确安装并正常工作非常重要。
3. 3. The double non-return valve prevents backflow during maintenance activities, ensuring a safe working environment.
   双回压阀在维护活动期间防止回流，确保工作环境安全。